Oxy fuel welding and brazing

[Fazerruss]

Morning all, I wondered if anyone knows the answer to this. Can you "weld" not solder aluminum with oxy propane and appropriate flux?
I know it can and used to be done in the old days before TIG with Oxy Accetylene but I curious if the use of propane would prevent it or cause problems.
Another question: Can you run an inline gas fluxer for brazing ( steel on steel with brass brazing rods) with Oxy propane? I know you can braze normally with oxy orpane and powered flux but from from what I've seen gas fluxes are much cleaner.

 

[frank horton]

I know an old ally body builder that just used oxy/accet and some kinda flux.....
he was gonna show me how if I worked with him for a week but he died soon after.....b shame....

 

[Erie Fred]

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[outofthefire]

You can weld ally with o/a but it's not easy. It's easier with the right type of welding glasses I think they're used in the glass blowing industry. The DCH2000 gas torch is supposed to make it easier as well, but they're not cheap. Can't help with the gas fluxer, but you can buy flux coated rods.

 

[pedrobedro]

You can weld ally with o/a but it's not easy. It's easier with the right type of welding glasses I think they're used in the glass blowing industry. The DCH2000 gas torch is supposed to make it easier as well, but they're not cheap. Can't help with the gas fluxer, but you can buy flux coated rods.

The glasses are blue instead of green there was a set at a place I worked. DCH2000 torch is just an overpriced overweight gimmick according to most reviews I've read and it doesn't look any easier to use than my Safire torch I've had forever.

 

[outofthefire]

The glasses are blue instead of green there was a set at a place I worked. DCH2000 torch is just an overpriced overweight gimmick according to most reviews I've read and it doesn't look any easier to use than my Safire torch I've had forever.

I've not tried gas welding ally, it was my mate. He raved about the henrob, but it did cost an arm and a leg.

 

[Fazerruss]

You can weld ally with o/a but it's not easy. It's easier with the right type of welding glasses I think they're used in the glass blowing industry. The DCH2000 gas torch is supposed to make it easier as well, but they're not cheap. Can't help with the gas fluxer, but you can buy flux coated rods.

I have flux coated rods already but it was just a question to satisfy my curiosity. From what I've seen of brazing with gas fluxes is it leaves a much cleaner finish without the black snot.

 

[Fazerruss]

I've not tried gas welding ally, it was my mate. He raved about the henrob, but it did cost an arm and a leg.

I weld Ali with the TIG but sometimes I get some very awkward old ali engine cases that won't weld with TIG

 

[zeppelin builder]

Morning all, I wondered if anyone knows the answer to this. Can you "weld" not solder aluminum with oxy propane and appropriate flux?
I know it can and used to be done in the old days before TIG with Oxy Accetylene but I curious if the use of propane would prevent it or cause problems.
Another question: Can you run an inline gas fluxer for brazing ( steel on steel with brass brazing rods) with Oxy propane? I know you can braze normally with oxy orpane and powered flux but from from what I've seen gas fluxes are much cleaner.

gas flux is not cheap the last 5 ltr can cost me over £70 came from france borax seems to be regarded as a nasty chemical now at one time you could get a box out the chemist

 

[metalmagpie]

I was taught that you need acetylene to weld. I am certain of that with steel but not quite certain about aluminum.

 

[Brad93]

I don't know if you'll melt the oxides or activate the flux with propane but there's only one way to find out.

You might find you need the flame temperature to keep the heat restricted to a small area. Remember propane puts out more BTU, but over a larger area. That could be problematic on a material like aluminium that becomes heat soaked, you're welding away and all of a sudden the whole lot goes molten and falls away due to the high heat output of the propane flame

 

[oldbikedavey]

I don't know if you'll melt the oxides or activate the flux with propane but there's only one way to find out.

You might find you need the flame temperature to keep the heat restricted to a small area. Remember propane puts out more BTU, but over a larger area. That could be problematic on a material like aluminium that becomes heat soaked, you're welding away and all of a sudden the whole lot goes molten and falls away due to the high heat output of the propane flame

Copper backing plates might help there.
Did watch a master at work on an aluminium Cobra body shell, and he was certainly using a very rich flame, and making it perform some most elegant waltzes....

 

[Keithmac]

My advice is to watch some Indian based repair videos on YouTube.

They seem very proficient at welding aluminium with a torch and some form of flux powder?.

I must admit I was amazed the first time I saw it..

 

[KH Forge]

I'm a bit late to this but I'll share my experience.

I have done a little bit of aluminum welding with OA. It's really not easy but doable, as mentioned above having blue glasses to cut the flux flare helps a lot as otherwise you really will struggle to see what's happening. I have tried it with a few different ali welding fluxes but the one I found worked best was CIGWELD Comweld Aluminum Flux (available in NZ and AU), I was recommended 1100 rods but I found 4043 worked a bit better, I don't think you can use 5356 as the magnesium won't play nicely with any oxy fuel process. As Brad mentioned you might find it difficult to keep the heat localised to your weld pool with propane, it's not easy with acetylene so you might need to play with your tip and flame size to find a sweet spot that works with propane. I do have an oxy LPG setup to so I might give it a go when I have some free time.

Brush flux on part, once you're close to welding heat, keep scratching at the surface with a flux covered rod until you see it flow, its hard to see as there's no cleaning action like you get with AC TIG so the oxide will kind of hide the molten pool until you push through it, the flux helps but doesn't stop or dissipate the oxide film. Once you have your weld going, keep moving quickly and take the heat off periodically to stop your entire part flowing onto your bench as if your not keeping an eye on it, the oxide layer will act as a thin film holding everything together until suddenly it doesn't and you get half you part flowing away.

I'd be really interested if you do succeed with oxy propane.

I wouldn't recommend OA (or oxy propane) aluminum welding unless you really want to and can spend a reasonable amount of time practicing as its kind of frustrating to start with and you won't produce good looking welds until you have spent a lot of time on the torch melting aluminum. If you do want to do it the best thing I can recommend is the blue glasses, I think I picked mine up for 30-50USD including shipping to NZ. I can find a link to them if you are interested.

I've been looking at an inline gas flux for brazing to. Unfortunately I haven't even found a company in NZ that sells gas fluxes and I'm not really wanting to try to ship HAZMAT internationally as it's pain just to do so around the country. I could bring in a fluxer or even build one but with out the flux the whole idea is currently dead in the water for me You guys a very lucky in Europe and the US/Canada for both range and pricing

 

[Stueeee]

I spent a week with Geoff Moss at MPH Motor Panels earlier this year. Geoff does all his Ali welding with OA. He uses a strip of parent metal as the filler. Having done a bit of Ali welding with OA in the past before I got a TIG setup, I was watching his technique intently. He uses this flux

The flux powder was mixed with water into a thin paste, painted on to the work and the filler strip with a brush immediately before welding. Even on 1.5mm Ali he was using a big (No.5 IIRC) nozzle and used a dragging scratching/scraping action with the filler rod. The welds were laid down at much greater speed than would be possible with TIG. IMO the real marker of Geoff's skill was the fact that he would flick the torch away momentarily every once in a while, obviously to avoid blowing a hole in the job, but I was watching intently without getting in the way, and I couldn't see what event was triggering that need. The best thing I can say about my days of ali welding with OA is that I after a while I got quite good at welding up holes

 

[Tigman]

My father was a dab hand , always O\A used , I tried years ago and honestly can't remember the technique used